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111.
Cross‐talk between monocyte invasion and astrocyte proliferation regulates scarring in brain injury
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Jesica Frik Juliane Merl‐Pham Nikolaus Plesnila Nicola Mattugini Jacob Kjell Jonas Kraska Ricardo M Gómez Stefanie M Hauck Swetlana Sirko Magdalena Götz 《EMBO reports》2018,19(5)
Scar formation after brain injury is still poorly understood. To further elucidate such processes, here, we examine the interplay between astrocyte proliferation taking place predominantly at the vascular interface and monocyte invasion. Using genetic mouse models that decrease or increase reactive astrocyte proliferation, we demonstrate inverse effects on monocyte numbers in the injury site. Conversely, reducing monocyte invasion using CCR2?/? mice causes a strong increase in astrocyte proliferation, demonstrating an intriguing negative cross‐regulation between these cell types at the vascular interface. CCR2?/? mice show reduced scar formation with less extracellular matrix deposition, smaller lesion site and increased neuronal coverage. Surprisingly, the GFAP+ scar area in these mice is also significantly decreased despite increased astrocyte proliferation. Proteomic analysis at the peak of increased astrocyte proliferation reveals a decrease in extracellular matrix synthesizing enzymes in the injury sites of CCR2?/? mice, highlighting how early key aspects of scar formation are initiated. Taken together, we provide novel insights into the cross‐regulation of juxtavascular proliferating astrocytes and invading monocytes as a crucial mechanism of scar formation upon brain injury. 相似文献
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Aor Pranchai Michael Jenke Juliane Vogt Uwe Grueters Lin Yue Ulf Mehlig Moirah Machado de Menezes Sven Wagner Uta Berger 《Wetlands Ecology and Management》2018,26(2):139-150
The global effort to rehabilitate and restore destroyed mangrove forests is unable to keep up with the high mangrove deforestation rates, which exceed the average pace of global deforestation. Although facilitation theory presents new possibilities for the restoration of heavily degraded mangrove sites, knowledge of tree–tree interactions in stressed mangrove forest ecosystems is too limited to utilize facilitation appropriately. The aim was to determine the mode of local interaction among stressed mangrove trees by investigating the effect of clustering on tree size and crown morphology under contrasting stand densities. The study was conducted in a dwarf Avicennia germinans forest in Northern Brazil, in which tree growth is limited by infrequent inundation and high pore-water salinity. Autoregressive regression, Voronoi tessellation and spatial point pattern statistics were used to address the spatial processes underlying tree interaction. Under low stand density (1.2 trees m?2) dwarf trees which grew in clustered cohorts of A. germinans had a less stunted crown morphology revealing the dominance of a positive neighborhood influence among plants. In contrast, dwarf trees in the denser forest stand (2.7 trees m?2) were interacting competitively as indicated by the more negative effect of neighbors on crown morphology and size. The shift from facilitative to competitive interactions is an important feature of mangrove forest regeneration under harsh environmental conditions. If mangrove trees are unable to regenerate naturally on severely degraded sites, intraspecific facilitation could be used to assist regeneration by planting seedlings in clusters and not evenly spaced. 相似文献
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Leucio D. Vieira Juliane S. Farias Diego B. de Queiroz Edjair V. Cabral Manoel M. Lima-Filho Bruna R.M. SantHelena Regina S. Aires Valdilene S. Ribeiro Juliana Santos-Rocha Fabiano E. Xavier Ana D. Paix?o 《生物化学与生物物理学报:疾病的分子基础》2018,1864(12):3577-3587
We investigated whether hypertension induced by maternal lipopolysaccharide (LPS) administration during gestation is linked to peripheral vascular and renal hemodynamic regulation, through angiotensin II?→?NADPH-oxidase signalling, and whether these changes are directly linked to intrauterine oxidative stress. Female Wistar rats were submitted to LPS, in the absence or presence of α-tocopherol during pregnancy. Malondialdehyde in placenta and in livers from dams and foetuses was enhanced by LPS. Tail-cuff systolic blood pressure (tcSBP) was elevated in the 16-week-old LPS offspring. Renal malondialdeyde and protein expression of NADPH oxidase isoform 2 were elevated in these animals at 20?weeks of age. Maternal α-tocopherol treatment prevented the elevation in malondialdehyde induced by LPS on placenta and livers from dams and foetuses, as well as prevented the elevation in tcSBP and the elevation in renal malondialdehyde in adult life. LPS offspring presented impairment of endothelium-dependent relaxation in aorta and mesenteric rings, which was blunted by angiotensin type 1 receptor (AT1R) blockade and NADPH oxidase inhibition. At age of 32?weeks, renal hemodynamic parameters were unchanged in anaesthetised LPS offspring, but angiotensin II infusion led to an increased glomerular filtration rate paralleled by filtration fraction elevation. The renal haemodynamic changes provoked by angiotensin II was prevented by early treatment with α-tocopherol and by late treatment with NADPH oxidase inhibitor. These results point to oxidative stress as a mediator of offspring hypertension programmed by maternal inflammation and to the angiotensin II?→?NADPH oxidase signalling pathway as accountable for vascular and renal dysfunctions that starts and maintains hypertension. 相似文献
116.
Fine Root Production across a Primary Successional Ecosystem Chronosequence at Mt. Shasta,California 总被引:1,自引:0,他引:1
Estimating changes in belowground biomass and production is essential for understanding fundamental patterns and processes
during ecosystem development. We examined patterns of fine root production, aboveground litterfall, and forest floor accumulation
during forest primary succession at the Mt. Shasta Mudflows ecosystem chronosequence. Fine root production was measured using
the root ingrowth cores method over 1 year, and aboveground litterfall was collected over 2 years. Fine root production increased
significantly with ecosystem age, but only the youngest ecosystem was significantly different from all of the older ecosystems.
Root production was 44.5 ± 13.3, 168.3 ± 20.6, 190.5 ± 33.8, and 236.3 ± 65.4 g m−2 y−1 in the 77, 255, 616, and >850-year-old ecosystems, respectively. Generally, aboveground litterfall and forest floor accumulation
did not follow the same pattern as root production. The relative contribution of fine root production to total fine detrital
production increased significantly with ecosystem age, from 14 to 49%, but only the youngest ecosystem was significantly different
from all of the older ecosystems. Fine root production was significantly correlated with some measures of soil fertility but
was not correlated with leaf or total litterfall, or forest floor accumulation. It was best predicted by soil N concentration
alone, but this relationship may not be causal, as soil N concentration was also correlated with ecosystem age. For the oldest
ecosystem, fine root production was also measured using the sequential intact cores/compartment-flow model method, and the
difference between the two estimates was not significant. Our study suggests that the relative contribution of fine roots
to fine detrital production, and hence to soil organic matter accumulation, may increase during forest primary succession. 相似文献
117.
Viktoria Michel Claudia Ulber Dietrich Pöhle Beate Köpke Katharina Engel Ute Kaim Ahmad Fawzy Sophie Funk Juliane Fornefett Christoph Georg Baums Tobias Eisenberg 《Antonie van Leeuwenhoek》2018,111(10):1955-1966
Rat bite fever is an under-reported, under-diagnosed emerging zoonosis with worldwide distribution. Besides Spirillum minus, Streptobacillus moniliformis is the major causative microorganism although it usually colonises rats without any clinical signs. A group of house rats (Rattus rattus) kept in a zoo exhibition for educational purposes suffered from neurological signs including disorientation, torticollis, stall walking, ataxia and death. Gross pathological and histo-pathological examinations of the investigated rats revealed high-grade otitis interna et media, from which Streptobacillus notomytis was isolated in pure culture or as the predominant microorganism. This case series underlines a previously expressed hypothesis that R. rattus might be naturally colonised with S. notomytis, whereas the traditional rat bite fever organism, S. moniliformis, might be restricted to the Norway rat (Rattus norvegicus). However, the general paucity of Streptobacillus isolates, especially from their respective animal hosts, precludes definitive proof of these host tropisms. This is the first report of S. notomytis detection outside Asia and Australia and the first evidence for its role as a facultative pathogen in house rats. 相似文献
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Katrin Schwichtenberg Torsten Wenke Falk Zakrzewski Kathrin M. Seibt André Minoche Juliane C. Dohm Bernd Weisshaar Heinz Himmelbauer Thomas Schmidt 《The Plant journal : for cell and molecular biology》2016,85(2):229-244
Short interspersed nuclear elements (SINEs) are non‐autonomous non‐long terminal repeat retrotransposons which are widely distributed in eukaryotic organisms. While SINEs have been intensively studied in animals, only limited information is available about plant SINEs. We analysed 22 SINE families from seven genomes of the Amaranthaceae family and identified 34 806 SINEs, including 19 549 full‐length copies. With the focus on sugar beet (Beta vulgaris), we performed a comparative analysis of the diversity, genomic and chromosomal organization and the methylation of SINEs to provide a detailed insight into the evolution and age of Amaranthaceae SINEs. The lengths of consensus sequences of SINEs range from 113 nucleotides (nt) up to 224 nt. The SINEs show dispersed distribution on all chromosomes but were found with higher incidence in subterminal euchromatic chromosome regions. The methylation of SINEs is increased compared with their flanking regions, and the strongest effect is visible for cytosines in the CHH context, indicating an involvement of asymmetric methylation in the silencing of SINEs. 相似文献
120.
Thomas Meyer Juliane Albrecht Gesine Bornschein Ulrich Sachsse Christoph Herrmann-Lingen 《Applied psychophysiology and biofeedback》2016,41(4):395-404
Diminished parasympathetic reactivity is a physiological feature of posttraumatic stress disorder (PTSD). The objective of this study was to compare female PTSD patients with non-traumatized healthy women with respect to autonomic cardiovascular regulation during exposure to two stressors. Hospitalized PTSD patients (n = 52) and controls (n = 37) completed standardized laboratory-based stress testing including a mental arithmetic test and a standardized audiotape recording of a crying infant. Controls and PTSD patients both showed a significantly increased heart rate and reduced pre-ejection period from baseline rest to the arithmetic stressor. However, as judged from nonsignificant changes in baroreflex sensitivity, parasympathetic activation caused by the crying infant stressor was blunted in PTSD patients as compared to healthy individuals. Under the crying infant condition, a vagal dominance was observed only in controls, and not in PTSD patients. Our data demonstrate that, in PTSD patients, diminished parasympathetic reactivity is not restricted to trauma-related events but can also be observed in response to a social stimulus such as listening to a crying infant. This finding suggests that the altered vagal reactivity in PTSD patients reflects the physiological consequences of a generally disturbed autonomous response to emotionally relevant stressors. 相似文献